/**
 * 发送get请求
 * @param {string} url 请求地址
 * @param {object} params 请求参数
 * @param {string|undefined} type 返回的接口数据类型
 * @param {object} headers 自定义请求头
 * @returns Promise
 */
function get(url,params,type,headers={}) {
    let temp = []
    for(let key in params) {
        temp.push(`${key}=${params[key]}`)
    }
    let paramsFilter = temp.join('&')
    const p = new Promise((resolve,reject) => {
        const xhr = new XMLHttpRequest
        xhr.onreadystatechange = () => {
            if(xhr.readyState === 4) {
                if(xhr.status === 200) {
                    let res = xhr.responseText
                    if(type === 'json') res = JSON.parse(res)
                    resolve(res)
                } else {
                    reject(xhr.status)
                }
            }
        }
        xhr.open('get',`${url}?${paramsFilter}`)
        for(let key in headers) {
            xhr.setRequestHeader(key,headers[key])
        }
        xhr.send(null)
    })
    return p
}
/**
 * 发送post请求
 * @param {string} url 请求地址
 * @param {object} params 请求参数
 * @param {string|undefined} type 返回的接口数据类型
 * @param {object} headers 自定义请求头
 * @returns Promise
 */
 function post(url,params,type,headers={}) {
    let temp = []
    for(let key in params) {
        temp.push(`${key}=${params[key]}`)
    }
    let paramsFilter = temp.join('&')
    const p = new Promise((resolve,reject) => {
        const xhr = new XMLHttpRequest
        xhr.onreadystatechange = () => {
            if(xhr.readyState === 4) {
                if(xhr.status === 200) {
                    let res = xhr.responseText
                    if(type === 'json') res = JSON.parse(res)
                    resolve(res)
                } else {
                    reject(xhr.status)
                }
            }
        }
        xhr.open('post',url)
        xhr.setRequestHeader('content-type','application/x-www-form-urlencoded')
        for(let key in headers) {
            xhr.setRequestHeader(key,headers[key])
        }
        xhr.send(paramsFilter)
    })
    return p
}

